Brazilian Jalap**Read before Scientific Section, A. Ph. A., Chicago meeting, 1918
Wilbur L. Scobille
1918
The Journal of the American Pharmaceutical Association (1912)
In I g 15 a brief article was published in the Pharnzaceutical Journal' of London by E. W. Holmes stating that Brazilian jalap had been for some time imported into Germany and used as a cheap source of resin of jalap. He had therefore procured some of the drug, which was identified as the root of Piptostegia pisonis and was examined chemically by Dr. F. W. Passmore. The latter found that the root contained over 2 0 percent of resin which answered to the U. S. P. & Ph. Br. tests for true resin
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... jalap, but only 85 percent of it was soluble in ether, and it contained 8.9 percent of ash. A search of pharmaceutical and chemical literature has failed to disclose any further account of this drug or its chemical composition. Accordingly a small amount was procured from Brazil and examined as follows: Forty grammes of the ground drug was exhausted with 95 percent alcohol in a Soxhlet apparatus and the tincture diluted to 200 mils. This tincture yielded 7.04 percent of dry solids equivalent to 35.2 percent of extractive in the drug, and on subjecting it to the U. S. P. method of assay for resin of jalap, gave 5.64 percent of resin in the tincture, equivalent to 28.2 percent in the drug. The resin was a light tuff color, slightly hygroscopic, and it melted under boiling water. Five hundred grammes of the drug was then extracted with alcohol, the tincture was concentrated by distillation to a syrupy liquid measuring about 180 mils. and this was poured slowly into about 7500 mils of cold water containing a little hydrochloric acid. The resin precipitated at first in a fine powder b r t quickly agglomerated into a sticky mass a t the bottom of the jar. It was washed several times with water, then collected and dried, yicliing 132.5 Gm. of resin, equivalent to a 26.5 percent yield from the drug. Portions of this resin were shaken with petroleum benzine, benzol, ether, chloroform, and acetone,.and the clear liquids evaporated. By this method it was found that 3.7 percent was soluble in petroleum benzine, 5.3 percent in tenzol, 5.9 percent in ether, 19.55 percent in chloroform, and 99.4 percent in acetone. It was nearly all soluble (97.5 percent) in a I percent solution of potassium hydroxide, and the addition of acid to this alkaline solution did not reprecipitate the resin. On shaking I Gm. of the resin, mixed with 5 Gm. of washed sand, with 100 mils of distilled water for several hours a t room temperature, and filtering, 0.535 Gm. was found to be dissolved by the water. This is a remarkable solubility for a resinous body, and probably accounts for the fact that it could not be precipitated as a powder, even in ice-cold water, but always sefarated as a soft, sticky mass. On ignition the residue yielded 0.5 percent of ash-considerably less than was obtained by Doctor Passmore. The acid number, as ohtaiiied by the U. S. P. process, was 23.1 and the saponification number was found to he 141.6. An alcoholic solution of the resin gave no color with a solution of ferric chloride and did not reduce Fehling's solution. But on heating the alcoholic solution with sulphuric acid a strong odor of valeric acid aCpeared and the ncutralized liquid reduced Fehling's solation, showing that the resin is of a glucosidal nature. Two grammes of the resin dissolved slowly in 10 mils of ammonia water, producing a cloudy but limpid solution, and the addition of an excess of hydrochloric acid did not precipitate the resin. Since the U. S. Pharmacopoeia requires that not more than 12 percent of the resin of jalap shall be soluble in ether, and not more than 30 percent soluble in chloroform, this resin of Brazilian jalap will meet the U. S. P. requirements except as to solubility in water and the acid-resin test, which it slightly exceeds. Even ~ * Read before Scientific Section, A. Ph. A" Chicago meeting, 1918. Pharm. Journal, 1915, page 671.
doi:10.1002/jps.3080070907
fatcat:efzt6jmhfnddtiq6zjj6urqwxq